It is known to enclose electrical and electronic components in a protective housing which, for example, is made of aluminum sheet metal coated with plastic, as disclosed in German Pat. No. 2,165,039, the housing being of a constant width along its longitudinal axis and having an opening which is closed by means of a resilient plug after insertion in the housing of the component. An assembly fixture in the form of a funnel-shaped conduit is placed over the opening of the housing, and the plug, which has a diameter larger than the housing neck diameter, is pressed forward through the funnel shaped conduit and is laterally compressed such that it is eventually firmly held under tension within the opening sidewall. In this method of assembly, it is necessary to place a tubular needle through the plug to place the inside of the housing in communication with the ambient atmosphere in order to allow the air within the housing which becomes compressed during insertion of the plug to escape to the ambient. The tubular needle must subsequently be removed which often results in damage to the plug or to the housing plastic insulation, especially in the vicinity of the housing opening rim as the tubular needle is preferably placed between the edge of the plug and the rim of the housing opening. As the component to be encapsulated is usually already attached to the resilient plug, pressing the resilient plug with the component attached thereto through the funnel-shaped conduit into the opening of the housing is a delicate and complicated process and, in addition, it is difficult to apply through the assembly fixture the desired high pressure which must be exerted on the plug in order to compact it enough to seal the relatively narrow opening of the housing.
It is the purpose of the present invention to provide a method permitting to mount electrical or electronic components in a housing and to seal the housing in a speedier manner, and to provide an improved sealing of the housing as well as to prevent damage from being inflicted to the plastic coating of the housing.